18.10 – Micro-lag with a new installation of Ubuntu Cosmic

I have recently upgraded (new installation) of Ubuntu 18.10 on my PC with the help of an Asus P8Z77-M motherboard (using Intel HD graphics), 24 GB of RAM and an Intel SSD.
However, I have noticed a lot of microlagging since the installation. For example, I am going to type and the letters being typed are sometimes delayed by one second. The music being played also pauses for one second before resuming.